Journal: A new way to detect alien life

Currently man searches for alien life in a way that often includes speculation and a lot of random data. However, we do have a scientifically accurate way to detect life. In physics, we learn that electron/photons change their behavior based on observation. (See http://www.youtube.com/watch?v=DfPeprQ7oGc
for and explanation.) So I offer this: How could one construct this test to see if light was observed by an alien race?